DE1135895B - Process for the preparation of a 2,3-epoxyalkanecarboxylic acid ester of an alkenol - Google Patents

Description

Process for the preparation of a 2,3-epoxyalkanecarboxylic acid ester of an alkenol The invention relates to a process for the preparation of 2,3-epoxyalkanecarboxylic acid esters of an alkenol whose olefinic group is separated from the ester group by at least one carbon atom of the 2,3 - epoxyalkanecarboxylic acid ester - glycidic acid ester is separated.

A common characteristic of oxirane compounds, i. H. Connections that one Group included is their great reactivity in numerous chemical reactions. It is known that the epoxy group reacts with alcohols, carboxylic acids, carboxylic acid anhydrides, amines, aldehydes, mercaptans, phenols and a number of other organic compounds as well as with water, mineral acids, hydroxides, ethers, alcoholates, phenolates. It is also known that epoxy groups undergo self-polymerization, d. H. homopolymerization, dimerization, rearrangement, in particular when acids, bases or heat exert a catalytic effect. Because of the relatively high reactivity of the epoxy groups, molecules containing these groups are often prepared in such a way that the epoxy groups are introduced by the final reaction and the reaction conditions are generally kept as moderate as possible to prevent further reaction of the epoxy groups to prevent or minimize their formation. If, for example, an epoxy ether is desired, the corresponding unsaturated ether is usually first prepared and this is then reacted with a peracid under mild working conditions to form the epoxy ether.

The process according to the invention for the preparation of a 2,3-epoxyalkanecarboxylic acid ester an alkenol whose olefinic group is at least replaced by one carbon atom of the alcoholic group is separated, is now characterized in that one 2,3-Epoxyalkanecarboxylic acid alkyl ester in the presence of an alkali or alkaline earth metal alcoholate with an aliphatic or cycloaliphatic containing an olefinic group Alcohol whose olefinic group has at least one carbon atom from the Hydroxyl group is separated, reacted with transesterification.

In view of the relatively strong reactivity of the epoxy groups and the numerous other easily occurring reactions of the epoxy compound participating in the reaction, such as e.g. B. self-polymerization, dimerization, rearrangement, reduction, it is surprising that the alkyl substituent of the epoxide is exchanged for the ethylenically unsaturated alcohol residue without the epoxy group being noticeably attacked. A review of the prior art reveals the astonishing and unexpected results obtained with the method of the present invention. The USA. Patent 2,680,109 describes one of the previously for the preparation of allyl-2,3-epoxybutyrate used methods. First, the production of 2-chloro-3-oxybutyric acid from crotonic acid and hypochlorous acid is described. The acid obtained is then treated with potassium hydroxide, the potassium salt of 2,3-epoxybutyric acid being obtained. The potassium salt is then converted to the corresponding silver salt, which is then converted to allyl 2,3-epoxybutyrate by treatment with allyl bromide in benzene solution. The disadvantages of this method are obvious. Melvin S. New in leads in his work on "The Darzens Glycidic Ester Condensation" (see "Organie Reactions" by Adams et al, Vol. 5, p. 425; published by John Wiley & Sons, Ine., 1952 ) from that the reduction of glycidic acid esters by treatment in alcohols with sodium should result in mixtures of the saturated acid and the corresponding primary alcohol. It is also stated that no details of the experimental procedure or the yields are reported. The author also mentions that ß, ß-diphenylglycidic acid ester should give ß, ß-diphenyl-x-oxypropionic acid by a similar reduction. Other literature references are also available which indirectly emphasize the patentability of the method according to the invention.

The expressions used are to be explained below. The alcohol used as the starting material for the present exchange reaction is either an aliphatic or a cycloaliphatic alcohol containing an ethylenic group, i. H. one Group, which is separated from the hydroxyl group of the alcohol molecule by at least one carbon atom. These include alkenyl, cycloalkenyl and cycloalkenylalkyl alcohols in which the ethylenic group is at least one carbon atom away from the hydroxyl group. These alcohols are usually referred to below for short as * olefinic alcohols "and the products obtained from them as a" glycidic acid ester of an olefinic alcohol "or as" 2,3-epoxyalkanoate of an olefinic alcohol ". The terms "glycidic acid ester of an olefinic alcohol" or "2,3-Epoxyalkanoat an olefinic alcohol" (the products obtained in the process) include those esters in which the carboxylic acid moiety of the ester in the 2- and 3-position has an oxirane oxygen atom, d . H. one Contains group in which all valencies of the epoxy carbon atoms are saturated by hydrogen and / or hydrocarbon groups; furthermore the olefinic alcohol radical of the ester, which is derived from either an aliphatic or a cycloaliphatic alcohol, contains an ethylenic group which is at least one carbon atom removed from the ester group and in which the ester molecule consists of carbon, hydrogen and oxygen atoms, wherein the oxygen atoms in the ester bond The aim of the invention is therefore a new process for the preparation of 2,3-epoxyalkanoates of an alcohol which contains an ethylenic group which is at least 1 carbon atom from the ester group of the ester molecule is removed. Furthermore, a new one-step process for the preparation of alkenyl, cycloalkenyl or cycloalkenyl alkyl 2,3-epoxyalkanoates is to be created, in which the corresponding alkyl 2,3-epoxyalkanoate with the corresponding alcohol in the presence of a catalytic amount of a metal alcoholate described below is implemented. In the new process for the preparation of the alkenyl, cycloalkenyl and cycloalkenyl alkyl 2,3-epoxyalkanoates mentioned, additional self-polymerization, dimerization, rearrangement, reduction and other undesirable side reactions are to be avoided or considerably reduced.

The 2,3-epoxyalkanoates which can be produced by the process according to the invention can be represented by the following structural formula: in which each valence of the epoxy carbon atoms is replaced by a hydrogen atom or a hydrocarbon group, namely an alkyl, cycloalkyl, aryl, aralkyl or an alkaryl radical, e.g. B. the methyl, ethyl, propyl, butyl, amyl, hexyl, 2-ethylhexyl, 2,3-dimethyloctyl, dodecyl, cyclopentyl, cyclohexyl, alkyl-substituted cycloalkyl, phenyl , Tolyl, benzyl, phenethyl, phenylpropyl radical is saturated and in which R is an alkenyl, cycloalkenyl or a cycloalkenylalkyl radical whose ethylenic group has at least one carbon atom from the ester group is removed, such as B. for an allyl-, ß-methallyl-, crotyl-, 3-butenyl-, 2-, 3- or 4-pentenyl-, 2-ethylhexenyl-, 4-oetenyl-, 2,4-dimethyl-5-octenyl -, alkyl-substituted cycloalkenyl, 2-cyclopentenyl, 3-cyclopentenyl, 3-cyclohexenyl, 6-methyl-3-cyclohexenyl, 5-butyl-3-cyclohexenyl, 6-methyl-3-cyclohexenylmethyl, 5- propyl-3-cyclohexenylmethyl, niedrigalkylsubstituierten 3 - cyclohexenylmethyl, 1 - methyl-3-cyclohexenyl, 1-methyl-3-cyclopentenyl, 1-cyclohexenyl niedrigalkylsubstituierten. In a preferred embodiment, R 3 and the acid radical can contain up to 12 carbon atoms up to about 20 carbon atoms. In a further preferred embodiment, the valences of the epoxy carbon atoms can be saturated by hydrogen atoms and / or alkyl radicals. It should be noted that the cycloalkenyl 2,3-epoxyalkanoates and the cycloalkenylalkyl and lower alkyl substituted cycloalkenylalkyl-2,3-epoxyalkanoates are new compounds which, by virtue of their dual function, i. H. because of their reactive epoxy and ethylenic groups, are used as polymerizable monomers in polymerization technology. These monomers can be polymerized with unsaturated compounds that contain a vinyl group, and then form solid polymers that can be shaped or cast into articles of daily use.

The 2,3-epoxyalkanoates which can be prepared by the process of the invention include, for. B. allyl 2,3-epoxypropionate, allyl 2,3-epoxybutyrate, methallyl-2,3-epoxypropionate, methallyl-2, -epoxypentanoate, methallyl-2-methyl-2,3-epoxybutyrate, crotyl-2,3 epoxypentanoate, crotyl 2-ethyl-2,3-epoxyhexanoate, 3-butenyl-2,3-dimethyl-2,3-epoxybutyrate, 3-butenyl-2-ethyl-4-methyl-2,3-epoxyheptanoate, 3 Pentenyl 2,3- epoxypropionate, 4 - pentenyl -2,3- epoxybutyrate, 2-methyl-3-butenyl-2,3-dimethyl-2,3-epoxyhexanoate, 2-pentenyl-4-propyl-2,3 epoxyheptanoate, 1-ethyl-3-butenyl-2,3-epoxyvalerate, 4-octenyl-2,4-diethyl-2,3-epoxyoctanoate, 2-cyclopentenyl-2,3-epoxypropionate, 5-amyl-3-cyclohexenyl 2,3-epoxyoctanoate, 3-pentenyl-2,3-epoxybutyrate, 2-ethyl-4-pentenyl-2-ethyl-2,3-epoxyhexanoate, 3-hexenyl-2,3-dimethyl-2,3-epoxybutyrate , 2-propyl-4-hexenyl-2-ethyl-2,3-epoxyvalerate, 3-cyclohexenylmethyl-2,3-epoxyheptanoate, 6 - methyl - 3 - cyclohexenylmethyl - 2,3 - epoxybutyrate, 4 - butyl - 2 - cyclopentenylmethyl - 2 - ethyl - 2,3 - epoxyhexanoate.

The alkyl 2,3-epoxyalkanoates suitable as reactants for the process according to the invention are characterized by the following structural formula: in which each valence of the epoxy carbon atoms has the same meaning as in the above formula (I) and in which R, for an alkyl radical, such as. B. .. a methyl, ethyl, propyl, butyl, isobutyl, amyl, hexyl, 2-ethylhexyl, 2,4-dimethyloctyl, nonyl, dodecyl, octadecyl radical.

Suitable alkyl 2,3-epoxyalkanoates are, for. B. methyl 2,3-epoxypropionate, methyl 2,3-epoxybutyrate, ethyl 2,3-epoxybutyrate, propyl-2-methyl-2,3-epoxybutyrate, 3-methylpentyl-2,4-dimethyl-2, 3-epoxypentanoate, isobutyl-2-ethyl-2,3-epoxyhexanoate, octyl-2, 4,6 - trimethyl - 2,3 - epoxyoctanoate, 2 - ethylhexyl-2,3 - epoxybutyrate, 3,5 - dimethyloctyl - 4 - propyl 2,3-epoxypentanoate, isooctyl 2,4,6-trimethyl-2,3-epoxydecanoate and the like.

The alkyl 2,3-epoxyalkanoates of the formula (II) can be prepared according to known methods Process.

The olefinic alcohols suitable as starting materials for the present process are the alkenyl, cycloalkenyl and cycloalkenylalkyl alcohols which contain an ethylenic group which is at least 1 carbon atom away from the hydroxyl group. It follows that the alcohol contains at least 3 carbon atoms and that allyl alcohol is the simplest alcohol that meets this requirement. Suitable olefinic alcohols are, for. B. the above-mentioned allyl alcohol and methallyl alcohol, crotyl alcohol, 3-butenol, 2-, 3- or 4-pentenol, 2-hexenol, 4-hexenol, 2-ethyl-4-hexenol, 2-methyl-4-octenol, 3 - Propyl - 5 - octenol, 9 - undecenol, cyclopentenols, 5-methyl-2-cyclopentenol, cyclohexenols, 4-butyl-2 - cyclohexenol, alkyl - substituted cycloalkenols, cycloalkenylmethanol, 3 - cyclopentenylmethanol, alkyl-substituted cyclohexenylmethanol, 1-methyl- 3-cyclohexenylmethanol and the like olefinic alcohols containing 3 to about 12 carbon atoms are preferred here.

The alkali and alkaline earth metal alcoholates are suitable as catalysts for the present epoxidation. The terms "alkali alcoholate" and "alkaline earth alcoholate" used in the description and claims refer to the alkali or alkaline earth metal derivatives of alkyl alcohols, alkenyl alcohols, cycloalkyl alcohols or cycloalkenyl alcohols, the ethylenically unsaturated group of these alcohols being at least 1 carbon atom away from the hydroxyl group. The production of these alcoholates is known. It is expedient to use an alcoholate whose alcohol corresponds to the olefinic alcohol used as the starting material. The catalyst can then simply by dissolving z. B. of sodium in an excess of the alcohol in question, so that the solution obtained contains both the alcoholic reactant and the catalyst for the exchange reaction.

Examples of useful metal alcoholates are e.g. B. the compounds of alkali and alkaline earth metals, such as. B. lithium, sodium, potassium, cesium, magnesium, calcium, strontium and barium, with alcohols such as methyl, ethyl, propyl, butyl, amyl, hexyl, 2-ethylhexyl, 3.5 - Dimethyloctyl-, dodecyl-, octadecyl-, allyl-, crotyl-, 2-, 3- and 4-pentenyl-, 3-heptenyl-, 4-octenyl-, 3-cyclohexenyl-, 2-cyclopentenyl-, 6-methyl- 3-cyclohexenyl, 6-methyl-3-cyclohexenylmethyl, 5-butyl-3-cyclohexenylmethyl alcohol and the like.

It can also be used catalyst mixtures such. B. those derived from mixtures of alcohol or mixtures of metals. If z. B. sodium alkoxide is added to the reaction mixture containing allyl alcohol, an equilibrium is created between the sodium alkoxide and the sodium allylate. For example A mixture of sodium allylate and potassium allylate would also be an effective catalyst result for the reaction.

The amount of catalyst used can span a wide range. In general, a catalyst concentration of from about 0, 1 to about 20 0 /, or more, based on the weight of the reaction mixture is suitable, with a concentration between about 0.5 and about 5.0 weight percent is preferred.

The proportional amounts of the reactants, d. H. the alkyl glycidate and the olefinic alcohol can also vary over a wide range. Although less than equimolar amounts of the olefinic alcohol in relation to the glycidic acid ester can also be used, a molar excess of the alcohol over the ester is preferably used. The excess olefinic alcohol accelerates the reaction and also serves as a diluent, which is removed from the reaction mixture by conventional means, e.g. B. by fractional distillation can be recovered. Molar ratios between about 1.5: 1.0 and about 10.0: 1.0 of the olefinic alcohol to the alkyl glycidic acid ester are preferred.

An inert organic diluent can also be used in the exchange reaction be used. Typical diluents suitable for this purpose are e.g. B. aliphatic and aromatic hydrocarbons, such as n-pentane, n-hexane, benzene; Ethers, such as diethyl ether, diisopropyl ether.

Practice has shown that the best working conditions depend to some extent on the relationship between various factors, such as: B. temperature, respective reactants, proportions of these reactants, respective catalyst, concentration of the catalyst. For effective results, the exchange reaction is preferably carried out at relatively low temperatures and under reduced pressure in order to prevent the alkyl glycidic acid ester from being significantly decomposed. A temperature between approximately 0 and 100 ° C. is suitable for this, with approximately 10 to 60 ° C. being preferred. The pressure depends of course on the alcohols used for the exchange and the desired working temperatures. If a device is used which e.g. B. consists of a still, which is connected to a distillation column to which a reflux condenser is attached, the exchange is preferably carried out by the reaction mixture at a temperature between about 20 and 125'C and a pressure of about 10 to 760 mm Hg is brought to reflux. The temperature of the bubble is preferably maintained at about 40 to 75 ° C. The pressure in the device can be the autogenous pressure generated by the alcoholic reactant at the temperature prevailing in the bladder. The reaction time is determined by the aforementioned variable factors and, to some extent, by the relationship between the operating temperatures and the pressure applied. The reaction is complete when the lower-boiling alcohol has essentially been removed from the reaction mixture or, if appropriate, beforehand. A reaction time of less than 6 hours is appropriate, but not necessary.

The desired product, the glycidic acid ester of an olefinic alcohol, can from the reaction mixture z. By distillation, usually after neutralization of the catalyst. The desired product can also be in the form of a Residue can be obtained after distilling off the excess alcohol. Of the The residue can then be removed by careful washing with a dilute aqueous acid and a dilute aqueous base to remove the impurities or by Crystallization can be purified.

The glycidic esters according to the invention according to formula (I) are valuable Links. These compounds are due to the reactive epoxy and olefinic groups in the molecule bifunctional. You can use other monomers, such as vinyl chloride, acrylonitrile, for the formation of copolymers that lead to different Objects that can be molded or cast can be polymerized. The invention Glycidic acid esters can also be homopolymerized to give hard polymers. Of the Glycidic acid esters can also be hydrolyzed to give the corresponding glycidic acids whose usefulness is known. It is known that epoxy groups in Presence of catalytic amounts of bases, especially when heated, self-polymerization subject or that dimerizations can occur with rearrangements. It is therefore common practice in the manufacture of epoxy compounds are the epoxy groups if possible only to introduce in the last reaction stage in order to prevent a change in these epoxy groups occurs through subsequent reactions. It was therefore very surprising that by the method according to the invention, in which in the Contrary to the usual procedure the epoxy groups already to an earlier one Time to be introduced into the molecule, despite the presence of the alkaline Catalysts the compounds according to the invention in such a simple manner and with such good yields can be produced. Compared to the previously known method for the preparation of these compounds, the process according to the invention provides a represent considerable technical progress.

Example 1 1.2 g (0.052 mol) of metallic sodium was dissolved in 580 g (10 mol) of anhydrous allyl alcohol in a 1-1 four-necked flask. After the sodium had completely reacted, 116 g (1 mol) of methyl 2,3-epoxybutyrate were added and the flask was then connected to a 30 cm high, unfilled distillation column which was provided with a reflux condenser cooled with a salt solution at -5.degree . The solution was brought to reflux at 65 mm Hg and the constituents of the mixture which boiled below the boiling point of allyl alcohol were drawn off at the top. This process took about 2 hours, and the bubble temperature was kept below 40 ° C throughout. Thereafter, even with total reflux, the temperature at the distillation head did not fall below the boiling point of the allyl alcohol.

Then 3.5 cc of acetic acid was added to the reaction solution in order to destroy the catalyst contained therein. The reaction solution was then distilled and, after removing the excess allyl alcohol, a fraction of 116 g was collected, which boiled between 36 ° C. at 40 mm Hg and 93 ° C. at 25 mm Hg. This fraction was then redistilled using a 45-2.7 cm column packed with approximately 3 mm stainless steel packing. In this distillation, 43 g of allyl 2,3-epoxybutyrate were obtained, which had the following properties - boiling point 96 to 97 ° C. at 25 mm Hg; nIDI 1.4362; Saponification purity 99.60 / 0; Purity by bromination 98.20 / ,; Purity by pyridine HCl method 95.50 /,; Infrared spectrum: corresponds to the spectrum expected for allyl 2,3-epoxybutyrate. Absorption band at 5.80 #t (ester carbonyl group), at 6.08 #t (carbon-carbon double bond); at 10.08 p. and 10.75 #t (vinyl group); at 11.6 #t and 12.8 #t (transepoxy group). The yield was 370/0.

If in place of the metallic sodium an equivalent molar amount metallic potassium is used, will give essentially the same results achieved.

Example 2 323 g (2.79 mol) of methyl 2,3-epoxybutyrate, 970 g (16.7 mol) of allyl alcohol and 5 g of sodium methylate were placed in a still and brought to reflux at a pressure of 50 mm Hg. At the top of the still part of the distillate was drained off until the boiling point of the allyl alcohol was reached. A further 12 g of sodium methylate were then added to the still and the reaction was continued in the same way as before until only allyl alcohol was present in the distillation head. Then, the majority of the excess allyl alcohol was removed and in this case 450 g of a product were obtained, the boiling in the range of 38'C / 50 mm Hg and 68'C / 5 mm Hg. This distillate was then subjected to fractional distillation and gave 228 g of allyl 2,3-epoxybutyrate with the following properties: boiling point 96 to 98 ° C. at 25 mm Hg: n3D11 1.4362. The yield was 58. Example 3 372 g (2.0 mol) of ethyl 2,3-epoxy-2-ethylhexanoate were added to a solution of 15 g of sodium methylate in 928 g (16 mol) of allyl alcohol. The mixture was brought to reflux in a distillation unit equipped with a 150 cm high fractionating column. At a pressure of 50 mm Hg, a mixture of ethanol and allyl alcohol was drawn off at the top of the system for 41 /, hours to 22 to 25 ° C. The reaction mixture was then rapidly freed from all of the allyl alcohol by distillation. The remaining allyl ester was stripped from the residue by flash distillation. A subsequent fractional distillation gave 317 g of allyl 2,3-epoxy-2-ethylhexanoate with the following properties: boiling point 70.degree. C. at 1 mm Hg, n'01 1.4402, purity through saponification 99.60 /. The yield was 80.0 "/ the theoretical amount.

Example 4 130 g (1.0 mol) of ethyl 2,3-epoxybutyrate, 378 g (3.0 mol) of 6-methyl-3-cyclohexenylmethanol and 10.0 g of sodium methylate were placed in a still and at a pressure of 40 mm Hg brought to reflux. A total of 42 g of a distillate (bp ".. # 20 to 23'C) were drawn off over the course of 31 /, hours, the bubble temperature being kept below 50'C throughout.

The catalyst was then destroyed by adding 10.8 g of acetic acid to the reaction mixture and this was then distilled. After removing the excess 6-methyl-3-cyclohexenylmethanol, a fraction of 122 g with a boiling point between 71 and 126 ° C. at 3 mm Hg was obtained. This fraction was then dissolved in a 35 - was filled with about 6 mm, the major triple twisted spirals 3.2 cm glass fractionation column, re-distilled to give 84.0 g of 6-meth yl-3-cyclohexenyl-2,3- epoxybutyrate with the following properties: boiling point 117'C at 2 mm Hg, n 30 1.4718, purity through saponification 99 "/" infrared spectrum: absorption peaks at 3.32 p., 5.78 #t, 6.06 V., 7 , 25 p " 8.4 # t1 11.6 11 and 15.1 li, which corresponded to the expected spectrum for 6-methyl-3-cyclohexenylmethyl-2,3-epoxybutyrate. There was no evidence of other groups or impurities present. Analysis for C "H, 803 Calculated ... C 68.60, H 8.57 found ... C 68.64, H 8.79 "; C 68.74, H 8.75%. The yield was 40 % of the theoretical amount. The above procedure was repeated except that after the catalyst was neutralized, the reaction mixture was flash distilled by dripping onto a hot surface maintained at 180 ° C. at 2 mm Hg. Another distillation gave 111 g of 6-methyl-3-cyclohexenylmethyl-2,3-epoxybutyrate with the following properties: boiling point 122 ° C. at 3.5 mm Hg, n3 '01.4718. The yield was 53% of the theoretical amount. Example 5 130 g (1 mole) of ethyl 2,3-epoxybutyrate, 165 g (1.92 moles) of 4-pentenol and 10.0 g of sodium methylate were placed in a still and refluxed at 40 mm Hg. A total of 39 g of a distillate (bp ".. = 19 to 23 ° C) were drawn off over the course of 3 hours; the kettle temperature was kept at less than 50 ° C throughout.

The catalyst was destroyed by adding 10.8 g of acetic acid to the reaction solution and then distilling it. A fraction with a boiling point between 70 ° C. at 48 mm Hg and 92 ° C. at 3 mm Hg was collected. This fraction was then treated with a 35 - was filled 3.2 cm large glass fractionation column with 6 mm wide, triple helices rotated, again distilled to give 57 g of 4-pentenyl-2,3-epoxybutyrate having the following properties: boiling point 96 ' C at 5 mm Hg; n1D1 1.4405; Purity by saponification 99 0 / ,; Infrared spectrum: showed absorption peaks at 3.5 V., 5.8 #L, 6.1 #t, 8.0 #t, 8.4 #t, 10.0 tL, 10.9 p., 11.6 p # , 12.8 Lt and 13.8 #L, which corresponded to the expected spectrum for 4-pentenyl-2,3-epoxybutyrate. There were no other groups or impurities present.

Another distillation of this product gave pure 4-pentenyl-2,3-epoxybutyrate with the following properties: boiling point 68 ° C. at 0.5 mm Hg, n3D11 1.4405. Analysis for C, H "0, Calculated ... C 63.5 1, H 8.29 0/1; found ... C 63.63, H 8.24 0 / ,. Example 6 130 g (1.0 mole) of ethyl 2,3-epoxybutyrate. 580 g (10.0 mol) of allyl alcohol and 0.75 g of magnesium methylate in 14.25 g of methanol were placed in a still and brought to reflux at a pressure of 50 mm Hg. At the top of the still part of the distillate was discharged until the boiling point of the allyl alcohol was reached. A further 0.75 g of magnesium methylate in 14.25 g of methanol was then added to the mixture and the reaction was continued in the same manner as before until only pure allyl alcohol was present in the top of the bubble. The reaction took a total of 4 hours.

The catalyst was destroyed with 2.20 g of acetic acid and the reaction mixture was then distilled. Most of the excess allyl alcohol was drawn off, and 111 g of a product were obtained without fractionation, the boiling point of which was between 60 ° C. at 15 mm Hg and 70 ° C. at 5 mm Hg. This distillate was then subjected to a fractional distillation and gave 89 - allyl 2,3-epoxybutyrate with the following properties: boiling point 97 ° C. at 25 mm Hg; n-'0 '1.4363; Purity by saponification 100 l) / ,; Purity by pyridine-H CI method 98 0 / ,. The yield was 68% the theoretical amount.

Claims (2)

PATENT CLAIMS: 1. A process for the preparation of a 2,3-epoxyalkanearboxylic acid ester of an alkenol, the olefinic group of which is separated from the alcoholic group by at least 1 carbon atom, characterized in that a 2,3-epoxyalkanearboxylic acid alkyl ester in the absence of an alkali or alkaline earth metal alcoholate with a an olefinic group-containing aliphatic or cycloaliphatic alcohol, the olefinic group of which is separated from the hydroxyl group by at least 1 carbon atom, with transesterification. 2. The method according to claim 1, characterized in that the reaction is carried out at a temperature between about 0 and 100'C and optionally at reduced pressure. 3. The method according to claim 1 and 2, characterized in that a lithium, sodium, potassium, magnesium or calcium alcoholate is used. 4. The method according to claim 1 to 3, characterized in that the alkenol, allyl alcohol, 4-pentenol, crotyl alcohol, cyclohexenylmethanol, 6-methyl-3-cyclohexenylmethanol, cyclopentenylethanol, cyclopentenol or cyclohexenol is used. References considered: U.S. Patent No. 2221,663; British Patent No. 736 397.